NC0004308_PCB Mass and Sampling Maps_20150713

URS
PRIVILEGED AND CONFIDENTIAL—ATTORNEY-CLIENT WORK PRODUCT
March 5, 2010
Charles D. Case,Partner
Hunton&Williams LLP
One Bank of America Plaza, Suite 1400
421 Fayetteville Street(27601)
P. O. Box 109
Raleigh,NC 27602
Re: Estimate of PCB Mass in Sediments of Badin Lake
Dear Mr. Case:
URS Corporation(URS)has completed estimates of PCB mass in sediments in the southwest
embayment of Badin Lake near the former Alcoa Badin Works. Sources of sediment PCB data
included the following:
— Sediment PCB data collected by Woodward-Clyde for Alcoa in 1996-1997 (WCC 1997)1
— Sediment PCB data collected by ESI for Stanly County in 2007(ESI 2008)2
— Sediment PCB data collected by URS for Alcoa Power Generating Inc. in 2008 (URS 2009)3
— Sediment PCB data collected by Entrix for Stanly County in 2009 (Entrix 2009)
A summary of PCB data is provided in Table 1. PCB sampling locations and concentrations are
presented in Figure 1 for Badin Lake, and in Figure 2 for a more detailed view of the southwest
embayment of Badin Lake. Key parameters for calculating the PCB mass within a specific area
of interest are sediment surface area,sediment depth,PCB concentration, sediment dry bulk
density, and a mass unit conversion(mg to kg):
[Area m2)*depth m)*concentration (44)*DryBulkDensity(r8)* llcg J =total mass(kg)
,,, 106 mg
WCC 1997.Preliminary Sediment and Water Sampling Results from Alcoa's Badin,North Carolina Works.
Prepared for Alcoa by Woodward-Clyde Consultants.
2 ESI.2008.Badin Lake Swim/Picnic Area and Badin Boat Access Sediment Assessment. Prepared for Stanly
County North Carolina,by Environmental Services,Inc.
3 URS.2009.2008 Sediment Data Report.Prepared for Alcoa Power Generating Inc.by URS.
4 Entrix.2009. Sediment PCB results transmitted via email from Mr.Thomas N.Griffin,III to Mr.John Dorney
dated April 30,2009.
URS Corporation
1000 Corporate Centre Dr.,Ste 250
Franklin,TN 37067
Tel: [phone]
Fax:[phone]
www.urscorp.com

Charles D. Case,Partner
Page 2 of 6
March 5, 2010
The sum of the masses for individual areas of interest represents the total PCB mass. Each of the
inputs is discussed below:
• Area of Interest: The area of interest is the southwest embayment of Badin Lake. PCBs
were not detected in areas outside of the embayment except as reported by Entrix(2009) (see
also Table 1). The 2009 samples collected outside the southwest embayment(samples BL-4
through BL-7) exhibited approximately the same PCB concentrations,ranging from about
0.0107 mg/kg,to 0.0219 mg/kg. The high end of this range was in the northwest arm of
Badin Lake,well upgradient from the Alcoa facility. Based on similarity and low
concentration,these are believed to represent anthropogenic background concentrations.
Interpretation of the 2009 data may also be confounded by blank interferences;much of 2009
data(reported as PCB congeners)was blank qualified,meaning that"the analyte was found
in the associated method blank at a level that is significant with respect to the method result."
Thus,PCBs reported outside the southwest embayment as reported in the 2009 dataset may
also be biased high due to blank interferences. In either case (i.e.,whether general
anthropogenic background or blank interferences), it was not a goal of this effort to
quantitate background levels.
Samples collected along Transect 2 (samples T2-Sed-0 and T2-Sed-1C,Table 1) from the
URS 2008 sediment investigation were reported as nondetect. These samples were located in
approximately the middle of the southwest embayment just north of the swimming cove(see
Figure 2).Using sediment PCB concentrations as a guide(see Figure 3),a boundary for
defining the overall area of interest was selected by extending a line from the eastern
shoreline of the embayment just east of BL-1 (0.110 mg/kg),north to the east of BL-3 (0.043
mg/kg), and then extending west and north of sample location T2-Sed-1C(nondetect; shown
as sample t2c on Figures 2 and 3),intersecting the west shoreline near sample locations SA-3
and NEP3 (both nondetect). This boundary was used to approximate the location at which
sediment PCBs were nondetect,or at background levels. The area to the south and west of
this boundary defined the area of interest within the southwest embayment.
Subareas within the embayment were developed based on PCB concentration contours
(Figure 3). Areas between contours represent sediments with similar PCB concentrations.
The contours,and sizes of the areas within the contours were generated using Geographic
Information Systems(GIS)software(see discussion regarding PCB concentrations).
• Sediment Depth: There is limited quantitative information regarding depths of sediments
within the southwest embayment(or in other parts of Badin Lake). However, several pieces
of qualitative information provide insight into sediment depth.In the report Preliminary
Sediment and Water Sampling Results from Alcoa's Badin North Carolina Works(WCC
1977),the following is noted relative to sediment sampling within Badin Lake:
"At several of the predetermined[sediment sampling]locations.... sediment was not found.
Indeed, much of the bottom appeared to be exposed rock with softer, depositional substrates
in relatively localized areas (especially in the swimming cove per se). "

Charles D. Case,Partner
Page 3 of 6
March 5,2010
WCC(2007) concluded that"soft depositional sediment(mud) is heterogeneously distributed
in the swimming cove and immediate vicinity.... deposits are relatively localized in three
areas." These were"the northern part of the swimming cove; the southern part of the
swimming cove; and the Outfall 011/012 area." The report also noted that"the basically
horizontal circulation observed in the swimming cove area....probably contributes to the
scarcity of depositional sediments and their tendency not to accumulate in the very shallow,
marginal areas". The report also indicated that bathymetric observations revealed relatively
steep side slopes along the margins which tended to minimize accumulations of depositional
sediments along the shore.
In a sediment investigation performed for Stanly County in 2007(ESI 2008),the following is
indicated:
"Sediments were not deep and estimated to be less than two feet in depth."
Thus,there appear to be localized depositional areas within the swimming cove and near
Outfalls 011/012,there are also many areas void of sediments (exposed rock), and in general,
sediments are less than 2 ft deep. Hydrodynamics and bath}nnetry(steep slopes)in the
southwest embayment minimize accumulations of sediments. For purposes of this
evaluation,sediment depths were assumed to average about 0.5 ft.
• Bulk Density: Bulk density was estimated from the measured moisture content of existing
sediment data(Table 2)assuming a particle density of 2600 kg/m3 and water density of 1000
kg/m3. The relationship between wet bulk density and moisture content is:
wet
=Pspw(1+M)
k
PsM I Pw
where ps is the sediment particle density, pw is the water density and M is the moisture
content. The corresponding dry bulk density is:
dry __ Ps Pw
Pbutk PSM +PM,
These formulas were applied to the measured moisture content values for the 2007 (ESI
2008)and 2008 (URS 2009)data sets to estimate bulk densities. Results are shown in Table
2. The median,average,maximum and minimum values for all samples are summarized
below for both wet and dry bulk density estimates.

Charles D. Case, Partner
Page 4 of 6
March 5,2010
Summary of Bulk Density Estimates
Wet Bulk Density Dry Bulk Density
Statistic (kg/m3) (kg/m3)
Median 1598 960
Average 1601 966
Maximum 1758 1217
Minimum 1545 876
PCB concentrations were expressed as mg/kg dry weight; therefore, dry bulk density was
used in estimating PCB mass. The average value of 966 kg/m3 was selected as a
representative dry bulk density value.
• PCB Concentrations—As noted previously, sediment PCB data collected from Badin Lake
are compiled and presented in Table 1. Average PCB concentrations were estimated using
interpolation techniques using GIS software. Sediment samples from nearly all of the
historical sediment PCB investigations were collected from the surface layer(i.e.,up to six
inches). However, a limited number of subsurface samples(NEP3,NEP5,NEP10,NEP17),
referred to as"bottom"samples,were also analyzed for PCBs as reported in WCC(2007).
These were defined as greater than 6 inches and were collected with a hand push corer(so
penetration would still be relatively shallow). For these four sample locations,PCB
concentrations in the surface and bottom samples were averaged for contouring purposes.
The average PCB concentrations for the southern area of Badin Lake were contoured using
the Spatial Analyst Extension of ESRI's ArcGIS 9.3.1. Three interpolation methods are
available for purposes of developing spatial relationships using Spatial Analyst: Spline,
Inverse Distance Weighted(IDW) and Kriging. Spline and IDW are considered
deterministic interpolation methods versus Kriging which is a geostatistical analysis method.
Spline was chosen for this analysis because the distribution of data in the target study area
was sufficient to support generation of a smooth surface.Use of the Spline method is
appropriate because there appears to be a correlation between distance from presumed
sources (i.e., outfalls)and PCB concentration. In addition,because the Spline method
assumes all points are related,the analysis results in more conservative estimates of PCB
concentrations as compared with the IDW approach. During the Spline process, three
additional parameters may be specified to control the output surface; spline type,weight and
the number of points. The spline type specifies which of the derivatives will be weighted
more heavily during surface interpolation. Of the two spline types,regularized and tension,
the tension option was selected. The tension option weights the first derivative calculation
criterion more heavily,thereby resulting in a reasonable approximation of the concentrations
in areas where no data exist. The weight controls the relative smoothness of the surface and
the third parameter,number of points,specifies the number of samples used to calculate a
given cell value in the interpolated surface. The following options were used in this analysis:
weight=25 and number of points= 12. Additional"boundary"conditions in the form of
zero value data points were also added to the data set to control interpolation of the surface.
These points were added:

Charles D. Case,Partner
Page 5 of 6
March 5,2010
• at the shoreline;
• to the estimated anthropogenic background boundary, specifically along the eastern
boundary of the area of interest(see discussion above and Figure 3); and,
• to distinguish between source areas (i.e.,to separate Outfalls 011/012 and Outfall 002 as
specific source areas).
All contours and surfaces shown on the figures are presented as generated by the spatial
analysis extension with one exception:the 0.10 mg/kg contour encompassing BL-1. This
point was originally contoured as a single isolated location. However,the direction of
transport is likely from south to north(i.e., in the direction of bathymetric relief[shallow to
deep] and water flow toward the dam);therefore,PCBs measured at this location are more
likely related to the southernmost outfall(Outfall 002). Associating this data point to the
southern data cluster expands the southern 0.10 mg/kg contour and results in a more
conservative estimate of PCB mass.
PCB concentration contours developed using the approach described above are shown in Figure
3 for the southwest embayment. A lake-wide view of the contours is presented in Figure 4.
With the input parameters discussed above(area, sediment depth,bulk density, and PCB
concentration),PCB mass in each subarea(i.e., each subarea being the cumulative area between
sediment PCB contours) of the southwest embayment was calculated as shown in Table 3. Note
that contour areas are shown in Table 3 in 0.25 mg/kg increments. Contours on Figure 3 are
shown in roughly 0.5 to 1 mg/kg increments for ease in visualization. The sum of the PCBs in
each subarea represents an estimate of the total PCB mass in the embayment. At an average
sediment depth of 0.5 ft,total PCB mass was calculated as 7.69 kg.
As with all estimates, there are uncertainties inherent in the assumptions applied. For example,
quantitative information regarding actual sediment depths is unavailable, although qualitative
data were available from which to make reasonable estimates. An average sediment depth of 0.5
ft was assumed;the actual sediment depth may be higher or lower,and alternate depths would
result in a higher or lower estimate of total PCB mass. Concentration contours are also a
function of the available data and mathematical approaches used to interpolate between sample
locations. On balance, the assumptions applied in this evaluation are believed to be reasonable,
and the results provide a reasonably representative estimate of the mass of PCBs in sediments of
the southwest embayment of Badin Lake.

Charles D. Case,Partner
Page 6 of 6
March 5,2010
If you have any questions,please feel free to contact me at 615/224-2107.
Sincerely,
URS Corporation
410
•
Carl . Crane
Senior Consultant

Table 1. Summary of Badin Lake Sediment PCB Data
Water Depth° Aroclor 1016 Aroclor 1221 Aroclor 1232 Aroclor 1242 Aroclor 1248 Aroclor 1254 Aroclor 1260 Total PCBs Sample
Sample ID Source Sample Date Moisture
(ft) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg)
Content
NEPI Surface WCC 1997 Jan.97 <10 - - - ND(<0.0014) ND(<0.0039) 0.0046 0.0058 0.0104
NEP2 Surface Jan.97 <10 - - - ND(<0.0023) 0.0221 0.0197 0.0120 0.0538
NEP3 Surface Jan.97 <10 - - - ND(<0.0014) ND(<0.0038) ND(<0.0031) ND(<0.0035) ND
NEP3 Bottom Jan 97 <10 - -- - ND(<0.0015) ND(<0.004) ND(<0.0032) ND(<0.0036) ND
NEP4 Surface Fall 96 <10 - - - N/A ND(<2.60) N/A ND(<2.60) ND
NEP5 Surface Jan.97 <10 - - - ND(<0.002) 0.093 ND(<0.0044) 0.157 0.250
NEPS Bottom Jan.97 <10 - - - ND <0.0018) 0.328 ND(<0.0039) 0.495 0.823
NEP6 Surface Jan.97 13 - - - ND(<0.002) 0.251 0.151 0.183 0.585
NEP9 Surface Jan.97 11 - - - ND(<0.0023) 0.053 0.078 0.073 0.204
NEP1O Surface Jan.97 12 - - - ND(<0.0023) 0.213 0.211 0.327 0.751
NEPIO Bottom Jan.97 12 - -- - ND(<0.0019) 0.034 0.045 0.060 0.139
NEPI]Surface Jan.97 <10 - - - ND(<0.0012) 0.051 0.0182 0.0118 0.081
NEP12 Surface Jan.97 14 - -- - ND(<0.0026) 0.097 0.257 0.044 0.398
NEP12 Surface(dup) Jan.97 14 - -- - ND(<0.0027) 0.175 0.545 0.114 0.834
NEP12 Surface(avg) Jan.97 14 - - - ND 0.136 0.401 0.079 0.616
NEP13 Surface Jan.97 25 - - - ND(<0.002) 0.166 0.394 0.062 0.622
NEP16 Surface Sept 96 23 - - - N/A ND(<2.20) N/A 430 4.30
NEP16 Surface(dup) Sept 96 23 - - - N/A ND(<.90) N/A 6.50 6.50
NEP16 Surface(avg) Sept.96 23 - - - N/A ND NM 5.40 5.40 _
NEP17 Surface Jan.97 16 - - - ND(<0.0028) 1.07 1.50 0.419 2.99
NEP17 Bottom Jan.97 16 - - - ND(<0.0022) 0.106 0.191 0.044 0341
NEP17 Bottom(dup) Jan.97 16 - - - ND(<0.0025) 0.138 0.269 0.073 0.480
NEP17Bottom(avg) Jan.97 16 - - - ND 0.122 0.230 0.059 0.411
NEP21 Surface Jan.97 21 - - - ND(<0.0027) 0.202 0.261 0.094 0.557
NEP22 Surface Jan.97 <15 - - - ND(<0.0017) 0.127 0.117 0.050 0.294
NEP23 Surface Jan.97 <15 - - - ND(<0.0014) 0323 0.204 0.064 0.591
NEP24 Surface Jan.97 <15 - -- - 3.35 ND(<0.023) 0.750 0.220 432
SA-1A ESI2008 Dec-07 5-10 - - - ND(<0.084) ND(<0.084) ND(<0.084) ND(<0.084) ND 61.1
SA-1B Dec-07 5-10 - - - ND(<0.087) ND(<0.087) ND(<0.087) 0.089 0.089 62.5
SA-1C (Note.sample Dec-07 5-1D - - - ND(<0.084) ND(<0.084) ND(<0.084) ND(<0.084) ND 61.4
£4-I(a� as<20depths
oned Dec-07 5-10 - - - ND ND ND 0.089 0.089 61.7
SA-2A Dec-07 5-10 - -- - ND(<0.093) ND(<0.093) ND(<0.093) ND(<0.093) ND 64.6
SA-2B Dec-07 5-10 - - - ND(<0.090) ND(<0.090) ND(<0.090) ND(<0.090) ND _ 63.7
SA-2C Dec-07 5-1D - - - ND(<0.095) ND(<0.095) ND(<0.095) ND(<0.095) ND 65.5
SA-2(avg) Dec-07 5-10 - - - ND ND NI) ND ND 64.6
SA-3A Dec-07 5-10 - - - ND(<0.088) ND(<0.088) ND(<0.088) ND(<0.088) ND 62.7
SA-3B Dec-07 5-10 - - - ND(<0.083) ND(<0.083) ND(<0.083) ND(<0.083) ND 60.5
SA-3C Dec-07 5-10 - - - ND(<0.091) ND(<0.091) ND(<0.091) ND(<0.091) ND 63.8
SA-3(avg) Dec-07 5-10 - - - ND ND ND ND ND 62.3
SA-4A Dec-07 5-1D - - - ND(<0.180) ND(<0.180) 0.720 ND(<0.180) 0.720 63.1
SA-4B Dec-07 5-1D - - - ND(<0.180) ND(<0.180) 0.840 ND(<0.180) 0.840 63.7
SA-4C Dec-07 5-10 - - -- ND(<0.190) ND(<0.190) 0.880 ND(<0.190) 0.880 64.7
SA-4(mg) Dec-07 5-10 - - - ND ND 0.813 ND 0.813 63.8
Page 1 of 3

Table 1. Summary of Badin Lake Sediment PCB Data
Water Depth' Aroclor 1016 Aroclor 1221 Aroclor 1232 Aroclor 1242 Aroclor 1248 Aroclor 1254 Aroclor 1260 Total PCBs Sample
Sample ID Source Sample Date Moisture
(ft) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg)
Content
BR-1A Dec-07 10-15 - - - 2.40 ND(<0.180) ND(<0.180) 0.520 2.92 64.1
BR-1B Dec-07 10-15 - - - 2.20 ND(<0.190) ND(<0.190) 0300 2.50 653
BR-IC Dec-07 10-15 - - - 1.50 ND(<0.190) ND(<0.190) 0.480 1.98 66.3
BR-1(avg) Dec-07 10-15 - - - 2.03 ND ND 0.433 2.47 65.2
BR-2A Dec-07 10-15 - - - ND(<0.100) ND(<0.100) ND(<0.100) ND(<0.100) ND 68.2
BR-2A(dup) Dec-07 10-15 - - - ND(<0.110) ND(<0.110) 0.200 0.120 0320 68.9
BR-2A(ate) Dec-07 10-15 0.320 68.6
BR-2B Dec-07 10-15 - - - ND(<0.110) ND(<0.110) ND(<0.110) ND(<0.110) ND 69.1
BR-2B(dap) Dec-07 10-15 - - - ND(<0.110) ND(<0.110) 0.170 ND(<0.110) 0.170 69.9
BR 2B(am) Dec-07 10-15 0.170 69.5
BR-2C Dec-07 10-15 - - - ND(<0.110) ND(<0.110) 0.150 ND(<0.110) 0.150 68.8
BR-2C(dup) Dec-07 10-15 - -- - ND(<0.100) ND(<0.100) 0.210 ND(<0.100) 0.210 68.4
BR-2C(rtvg) Dec-07 10-15 0.180 68.6
BR-2(avg) Dec-07 10-15 - - - ND ND 0.183 0.120 0.223 68.9
11-1A Dec-07 10-15 - - - ND(<0.077) ND(<0.077) ND(<0.077) ND(<0.077) ND 57.5
R-1A(dup) Dec-07 10-15 - - - ND(<0.098) ND(<0.098) ND(<0.098) ND(<0.098) ND 663
R-1B Dec-07 10-15 - - - ND(<0.120) ND(<0.120) ND(<0.120) ND(<0.120) ND 73.1
R-1B(dup) Dec-07 10-15 - -- - ND(<0.110) ND(<0.110) ND(<0.110) ND(<0.110) ND 70.7
R-1 C Dec-07 10-15 - -- - ND(<0.120) ND(<0.120) ND(<0.120) ND(<0.120) ND 73.5
R-1C(dup) Dec-07 10-15 - - - ND(<0.110) ND(<0.110) ND(<0.110) ND(<0.110) ND 70.5
R-1(air) Dec-07 10-15 - - - ND ND ND ND ND 68.6
T1-SED-0* URS 7009 Dec-08 <0.0594 <0.0594 <0.0594 <0.0594 <0.0594 <0.0594 <0.0594 ND 44.46
TI-SED-1 C Nota Sediment Dec-08 30 <0.106 <0.106 <0.106 <0.106 <0.106 <0.106 <0.106 ND 68.76
T2-SED-0* texture reported Dec-08 <0.0994 <0.0994 <0.0994 <0.0994 <0.0994 <0.0994 <0.0994 ND 66.79
T2-SED-1C as silty clay with Dec-08 53 <0.111 <0.111 <0.111 <0.111 <0.111 <0.111 <0.111 ND 7038
T3-SED-0* varying organic Dec-08 <0.112 <0.112 <0.112 <0.112 <0.112 <0.112 <0.112 ND 70.54
T3-SED-1C material generally Dec-08 58 <0.116 <0.116 <0.116 <0.116 <0.116 <0.116 <0.116 ND 7143
T4-SED-0* increasing withDec-08 <0.101 <0.101 <0.101 <0.101 <0.101 <0.101 <0.101 ND 67.23
water depth.
T4-SED-1D Dec-08 90 <0.14 <0.14 <0.14 <0.14 <0.14 <0.14 <0.14 ND 76.47
T5-SED-0* Dec-08 <0.322 <0322 <0.322 <0.322 <0.322 <0.322 <0.322 ND 69.23
T5-SED-I E Dec-08 109 <0.119 <0.119 <0.119 <0.119 <0.119 <0.119 <0.119 ND 72.19
T6-SED-0* Dec-08 <0364 <0364 <0364 <0.364 <0364 <0364 <0.364 ND 72.77
T6-SED-0*-DUP Dec-08 <0.0804 <0.0804 <0.0804 <0.0804 <0.0804 <0.0804 <0.0804 ND 58.96
T6-SED-1B Dec-08 89 <0.138 <0.138 <0.138 <0.138 <0.138 <0.138 <0.138 ND 76.12
T7-SED-0* Dec-08 <0344 <0344 <0344 <0344 <0344 <0344 <0344 ND 71.23
T7-SED-IC Dec-08 114 <0.12 <0.12 <0.12 <0.12 <0.12 <0.12 <0.12 ND 72.53
T8-SED-0* Dec-08 <0.158 <0.158 <0.158 <0.158 <0.158 <0.158 <0.158 ND 58.2
T8-SED-1B Dec-08 128 <0.13 <0.13 <0.13 <0.13 <0.13 <0.13 <0.13 ND 74.66
T9-SED-0* Dec-08 <0.138 <0.138 <0.138 <0.138 <0.138 <0.138 <0.138 ND 52.03
T9-SED-1C Dec-08 135 <0.0983 <0.0983 <0.0983 <0.0983 <0.0983 <0.0983 <0.0983 ND 66A2
T 10-SED-0* Dec-08 <0.158 <0.158 <0.158 <0.158 <0.158 <0.158 <0.158 ND 5832
T10-SED-1C Dec-08 169 <0.119 <0.119 <0.119 <0.119 <0.119 <0.119 <0.119 ND 72.16
Page 2 of 3

Table 1. Summary of Badin Lake Sediment PCB Data
Water Depth' Aroclor 1016 Aroclor 1221 Aroclor 1232 Aroclor 1242 Aroclor 1248 Aroclor 1254 Aroclor 1260 Total PCBs Sample
Sample ID Source Sample Date Moisture
(ft) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg)
Content
BL-1** Entrix2009 Apr-2009 — — — — — — — 0.110
BL-2** Apr-2009 — — — — — _ — — 0363
BL-3** Apr-2009 — — — — — — — 0.043
BL-4** Apr-2009 — — — — — — — 0.0185
BL-5** Apr-2009 — — — — — — — 0.0107
BL-6** Apr-2009 -- — — — — — — 0.0144
BL-7** Apr-2009 — — — — — — — 0.0219
Cells presented in bold italics represent average values.
Surface-Generally top 6 in.
Bottom->6 inches
•Composite sample derived from 5 subsamples along each transect-depth varied among subsamples.
••Congener analyses-Aroclors not reported.
a-Water depths estimated from bathymctric profiles in WCC 1997,except NEP22.23.24.which were assumed to be less than 15 ft based on observations in ESI 2008 which reported depths in this area of 10-15 ft.
Page 3 of 3

Table 2-Bulk Density Estimates
Sample ID Source Moisture wet Bulk thy Bulk
Content Density(kg/ma) Density(kg/m3)
SA-1A ESI2008 61.1 1630 1012
SA-1B 62.5 1621 998
SA-1C 61.4 1628 1009
SA-2A 64.6 1608 977
SA-2B 63.7 1614 986
SA-2C 65.5 1603 969
SA-3A 62.7 1620 996
SA-3B 60.5 1634 1018 _
SA-3C 63.8 1613 985
SA-4A 63.1 1617 992
SA-4B 63.7 1614 986
SA-4C 64.7 1608 976
BR-1A 64.1 1611 982
BR-1B 65.3 1604 971
BR-1C 66.3 1598 961
BR-2A 68.2 1588 944
BR-2B 69.1 1583 936
BR-2C 68.8 1584 939
R-1A 57.5 1654 1050
R-1B 73.1 1562 902
R-1C 73.5 1560 899
T1-SED-0* URS 2009 44.46 1758 1217
Ti-SED-1C 68.76 1585 939
T2-SED-0* 66.79 1596 957
T2-SED-1C 70.38 1576 925
T3-SED-0* 70.54 1575 924
• T3-SED-1C 71.43 1570 916
T4-SED-O* 67.23 1593 953
T4-SED-1D 76.47 1545 876
T5-SED-0* 69.23 1582 935
T5-SED-1E 72.19 1566 910
T6-SED-O* 72.77 1563 905
T6-SED-1B_ _ 76.12 1547 878
T7-SED-0* 71.23 1571 918
T7-SED-1C 72.53 1565 907
T8-SED-0* 58.2 _ 1649 1042
T8-SED-1B 74.66 1554 890
T9-SED-0* 52.03 1694 1114
T9-SED-1C 66.42 1598 960
T10-SED-0* 58.32 1648 1041
TIO-SED-1C 72.16 1567 910
median 1598 960
average 1601 966
maximum 1758 1217
minimum 1545 876

Table 3-PCB Mass Calculations for Southwest Embayment
Sediment Average PCB Sediment dry Unit
Contour Interval Area 2 Depth Mass
(mg/kg) (ha) Area(m) P Concentration bulk density Conversion (kg)
(m)a (mg/kg) (kg/m3) (kg/106 mg)
less than 0.10 10.391 103910 0.1524 0.050 966 1000000 0.76
0.10 to 0.25 2.319 23190 0.1524 0.175 966 1000000 0.60
0.25 to 0.50 1.461 14610 0.1524 0.375 966 1000000 0.81
0.50 to 0.75 0.500 5000 0.1524 0.625 966 1000000 0.46
0.75 to 1.00 0.268 2680 0.1524 0.875 966 1000000 0.35
1.00 to 1.25 0.201 2010 0.1524 1.125 966 1000000 0.33
1.25 to 1.50 0.163 1630 0.1524 1.375 966 1000000 0.33
1.50 to 1.75 0.137 1370 0.1524 1.625 966 1000000 0.33
1.75 to 2.00 0.118 1180 0.1524 1.875 966 1000000 0.33
2.00 to 2.25 0.104 1040 0.1524 2.125 966 1000000 0.33
2.25 to 2.50 0.092 920 0.1524 2.375 966 1000000 0.32
2.50 to 2.75 0.082 820 0.1524 2.625 966 1000000 0.32
2.75 to 3.00 0.073 730 0.1524 2.875 966 1000000 0.31
3.00 to 3.25 0.066 660 0.1524 3.125 966 1000000 0.30
3.25 to 3.50 0.058 580 0.1524 3.375 966 1000000 0.29
3.50 to 3.75 0.051 510 0.1524 3.625 966 1000000 0.27
3.75 to 4.00 0.045 450 0.1524 3.875 966 1000000 0.26
4.00 to 4.25 0.040 400 0.1524 4.125 966 1000000 0.24
4.25 to 4.50 0.035 350 0.1524 4.375 966 1000000 0.23
4.50 to 4.75 0.026 260 0.1524 4.625 966 1000000 0.18
4.75 to 5.00 0.022 220 0.1524 4.875 966 1000000 0.16
5.00 to 5.25 0.018 180 0.1524 5.125 966 1000000 0.14
5.25 to 5.50 0.008 80 0.1524 5.375 966 1000000 0.06
Total Area 16.278 ha Total Estimate PCB Mass(kg) 7.69
a-0.1524 m equals 0.5 ft

s
C �-- :� • r 464,-:a Locator Map
s it $>�'
•
� RAj -t-,;.--~
•
,i * `' Mr ,
t�yJ
•
\ A-• r 7t ":i NORTH CAROLINA
....1,-".-..-. iT - - Legend
?• ,_ • \.\ � ! w, .._• T. PCB Sediment Sample(mg/kg)
6
-4 Fy'"-- �, ca �•,\• O 0-0.25
•'.`• .17F. ."1"°47,---
, w 0 0.25-1,00
•••;"—. • L: ® 1,00-2.50
, • 2,50-5.40
s , s.' .` Sample Transect
-a� i, �. .` (T-1=Transect 1)
,..,1'44.4.1' ` •�'",i a. ® Plant Boundary
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this
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*/ -. ,,; ; "r �::1 ; Alcoa-Badin Works
A� �; ��,- { r � Badin,North Carolina
„sot,'
_ "� ..'^. -ot�_ r. +. �,".Y, '- t coobieaze sys�om:
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,NEP1,_ Locator Map
„ 0:0104
/r ti NEP3
♦ Swimming l • NEP2 • `• B a L� f 77
0. i� 0:0536
t` Cove •.,t;.4,:, Lake
< ! " . SA-3
i . NEPfi �:2 t2c
/ o a: i 0:585 ND
Outfall 013 . ‘s s _ NEP,10 • NORTH CAROLINA
�. - 'zy. Cos
/- ?-..^; ` '" •NEPS • • * • Legend
/' • ♦ ,(:).5365
'_ '-_ ♦ : ' �""-* SA-2 NEP9 PCB Sediment Sample(mg/kg)
ND. 0.204 •
O 0-0.25
-` 0
' }1 • r - NEP13
_ N EP.11 y: 025-1.00
'''';."`i'.
ear ,.� _ �0081r. NEP12 Oifi22 _ .. �,
r5 •.f >V + 0615 ® 0 1.00-2.50
{;~:. ,- 5 40.0 3" 6
P16 0.33 • 2.50-5A0
5.40
I� i ',, ;� 0.8133 ® Sample Transect
. - ,,/ • (f-1=Transect 1)
•
NEP21�"•
❑ Outfalli // p ‘" NE117 0.557 7 � *f,,.. i I 1%99e ••••• Diffuse
r^ / ti'
Outfalls 011 and 012 ® Plant Boundary
:, �: t
f* ^ '� {t 1 I67. ND-Not Detected
*1 Ili
Ill �_ BL 1
0-1,10 . :.4.,..1,:: .,' > • -
ND
.11.
, 7 _ "$'� %7"k-.'-'4 ::-i-;.-.4-
` V'!iii 141111 L.5-e _ `s, ',• ..rim
''�' . :A... ' '
orf1
��R, _ t �a.. -r Y- - t '`� .T• e. . 0 250 500 Feet N
' , - ter. ••fiti. .
-e, '
,i BR-2 .101i,:71111.11.....1' "-"`a 0 0:05 0.1 Mlles
...,.,..... to NEP22 0.2233 - .-.. '
"`• a Outfall 002 . 0294
• Figure2
k1,r 1 ",n ,r•::„4.1 9. .: • NEP24 .'°'�.' •"-
t""'t$- u +_"r ... r ,J • 4.32 `'r, ; fl• PCB Concentrations
ter. �,. :l .. "NEP23 -_ ""r, a _c
ry;
li 0BR-1 istori diment S p es
597 � Hcal Se am- 1/ " 'l .. a� 3► ' Alcoa-Badin Works
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I / / a-_ 4 ,V,-,,,*
;,,,. ,,,,,. ::.� • � .__ __$' Li Envimneering Inc.and NC One Map

{ " ' NEPi•! Locator Map
r o:oio<ti
-4415‘,...
�l / • 4 k NEP2 • \ Sad ! /1
�t \` f o:ossa Lake 7•
''J
/r \a; T _ �2 ND \ •
/ i \` •'+r'?NO .S• ,::
\' NEP,G
/ s. rr . No SA 1 0.585113
/ r \ 0989 % \ • NORTH CAROLINA
/ - \NEP5 SA-2 ----46..0:445 •
-. "^ 0.5365 ND • ' \ Legend
��\ h NEP,u 1 PCB Sediment Sample(mg/kg)
\�,•y
0.'04 • 0 0.00-0.10
7
t
0
• 0.1.0-0.25 A NEP3
•
+��t��\ r •0�0811� 0NEPa
1612 0 0S 025-1.00'.r • 1.00-2.50
2.50-5.40
. A `p/�NEP r �aB30B:L0433
.. 1. PCB Concentration
•
(mg/kg)
r ` � 1,1E1.,.21\ I ,‘00
_ 1, /
V
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% 0557 t IIII
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C Sy 5.4
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4 k x' , '�, PCB Concentration Contour
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y r
f / i -_n •J I • ! me_.. Diffuser
e I ® Plant Boundary
--' / Area of Interest
n. 0.110 / • / ND-Not Detected
pr, r • "r, _ - ND -u ~ t
le A
- ---- - /.. �- _.
.j, :yam ��l{
lir
•
`T
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"y. .- •a +� 0 250 500 Feet N
,��+{ 4 --�4,„,,.' .� NEP ONEP,, ;0.2233 �� r. +uc * -- 0 0.05 0.1 Mika
•
�; 1 ;°5`'� •. •°o7 +ci* - `' �" Figure 3
a ,^► l $ T.7.---011.111110 IA I .. - `' PCB Isoconcentrations
a'4--34••‘••••
•• • 1 --. NEP 24 / - _ f x s ' _
� , BP=, ,'• ` --__ _..,•'-'iHistorical Sediment Samples
i 4667 0 50 -� p • : w±�
''...;Ti
r q e- \ ate— • Alcoa-Badin Works
J a°`� - d -" ;„ '`� '�` !�. . • - - F,. f ,,;.; Badin,North Carolina
Pr.- i•4' , G' .it. , ... .,..5?...:-..,,,,,...- -1 - .�. .'�� `r� � ....
.'. %w, Coeniine a System:
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_ s Locator Ma
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-..**„...„..-•
+1a ''."- r= -
-
�' L { NORTH CAROLINA
,.,.--.7,-
. 'kry*'-7�••p .. '"d '-` \: Legend
. r _ PCB Concentration(mg/kg)
Mora
' ® Plant Boundary
v
•
i.
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,Ir * '''*.K 1 lic ' :. ''51. . .- \
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z I
,, 45-4
r o zoao 4,000 Feet N
4,4"».N--$17--,-...,
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.. �: -` ',. - !• P :' ,•_s•- 0 025 0.5 Miles `\
I� �4 �, ..mob .,fir Figure 4
?' 't f �s . ,r PCB Sediment Samples
.-1--;- , e• ` e -. =`-e' ti Lake View, Badin Lake
Alcoa-Badin Works
"4%1 .X„", "4-(A '.5,. • y d; ny _ P'-'7" i Badin,North Carolina
o , Coordinate System•
�••G, .., r°�'l/ .�, 1. a- _ +� OA,'•,. 7 Geographic VJGS 1884
v -. �P �'a'lY II � -Lr' K -.. t r' Envirorroeringlnc.and NC One Map